Dental instrument



Aug. 21, 1928.

H. E. S. CHAYES ET AL DENTAL msTRUME'NT Filed Sept. 4, 1924 2 Sheets$he-et INVENTOR Aug. 21, 1928.

H. E. S. CHAYES ET AL DENTAL INSTRUMENT Filed Sept.l 4, 1924 2 Sheets-Sheet 2 v m In d m Al IHM-- l w f. V woVf/,\\`/Ww/. f

Patented ug. 21, 1928.

UNITED STATES PATENT orrlcE.

Hmmm: E. s. cnnns im AUGUST P. Junonnsnm or Nnw Yon-1r, N. Y., AssIeNons, :BY IEsNE Assia/uname, To enanas DENTAL INSTRUMENT eonro'miTIoN, or new You, it.` Y., A conPonATIoN or DELAWARE.

DENTAL INSTBUIENT.

Application and september 4, 1m. serial 1u. 735,847.

This invention relates to the construction of dental drill heads.

A general object of the invention is to provide a dental drill `head or hand-piece in which improvements are incorporated throughout the entire organization of structure. i

A feature of the inventionis the provision of a spindle construction in which the spin- `dle parts and tool held thereby are brought into mutual axial alignment in the act of bringing the chuck into gripping relation with the shank of the tool.

Another feature of the invention resides in a constructional arrangement which provides for disassembling the device without the use of tools. A,

Another feature ofthe invention resides in a constructional arrangement which provides for assembling the device without the use of tools.

vAnother feature resides in the use of a driving pulley provided with a` protective sleeve for normally enclosing and guard-` ing a bearin adjusting device.

Another fature resides in thervuse ofan all-metal construction to provide for the complete sterilization of the device. y

Another feature resides in the provision of bearings for the spindle located adjacent the extreme end portions thereof in order to provide the most effective support for the spindle when in rotation.

Another feature includes a unitary structural formation of the hand piece the greater portion of which is formed of lightweight metal whereby a desirable lightness in wei ht is achieved.

Stil another feature resides in theprovision of a removable chuck memberwhich is readily extractable" from the spindle housf in at the rearmost end thereof.

till other featuresof the invention will be hereinafter referred to. Y

In the drawin lin which a preferred embodiment of t e invention has been Selected for illustration,

Figure 1 is aview in lon tudinal section of a dental drill head ein `ying the invention.-

Figure2 is a viewin side elevation and on a reluced scale of the device shown in Figure Figure 3 y is a viewwin crosssection taken ont e line 3-3 of Figure l.

Figure 4 is a view 1n cross-section taken on the line 4-4of Figure 1.A l l igure 5 is a longitudinal sectional view showing in detail the construction of spindle and `chuck parts with a tool held in place in the chuck.

igi'ures 6 and 7 are views similar to Figu re 5 showing further details of construction.

Figure 8 is a yview in crossLsection taken on the line 8-y-8 of Figure 5.. t u

igure 9 is a view' similar to Figure 5 showing the bearing support for the spindle.

Figure 10 is a sectional viewon an enlarged scale showing a detail of constructiva Figure 11 is a view inside elevation of the `parts shown inFigure 10. y

Figure 12 is auview rin cross-section taken onthe line 12s-12 lof Figure 10. i

Referring to the drawings for a more detailed description ofy the invention, in Figures 1 and 2 a dental dri-ll head or hand pieee is shown which includes an elongated one-'piece cylindrical easing l() having a grooved and knurled portion 1l which ,facilitates the firm holding of thfe drill head in the hand of the operator. The cylindrical casing member l0 is provided at its forward end with a tapering end section 19. formed of stainless steel or the like and ar'-v ranged to serve as a bearing member in which the forward end of the spindle structure is journaled. The bearing member l2 is seated lin a screw-threaded relation in the forward end of the casing 10 as at 13.

The cylindrical casing member 10 is preferably formed of duralumin or some other metal of metal alloy having a relatively light weight characteristic. The rearward end of the casing l0 is fitted with a sleeve 14' formed of bronze or the like having a drive fit with said casing and adapted to serve as a journal havinlg` a swiveled relation with an angular brac et member 15 which is in tremities turn swiveled on a supporting shaft 16 eX- tending at right angles to the axis of the casing 10.

The rearward end of the casin is screw-threadedas at 16L to receive a` caring bushing 17 which may be longitudinally adjusted in its seat in the end of the casing 10 by reason of the screw-threaded relationreferred to. In order to lock the bearing busbing 17 in a desired adjusted position a lock nut 18 carried by the bushing 17 on a section thereof which protrudes from the endiof the casing 10 is adapted to bear against the adjacent ends of the casing 10,1'bronzesleeve 14,

a and an end of the bracket member 15. By

this arrangement the 'lock nut 18 serves not only to hold the bearing bushing 17 in its adjusted osition but the lock nut also holds the swive ed parts 14`and 15 intheir operable relation, the other end of the engaged portion of the bracket member bearing against a shoulder 19 formed for the purpose on the bronze sleeve 14.,

The bearing bushing 17 forms a bearing for the sleeve 2O which is driven tightly onto a hollow spindle member 2l so that the` spindle member 21 is free to rotate within the bearing bushing 17. The forward end of the hollow spindle member 21 is provided "with an extended journal piece 22 which 1s journaled in the bearing member 12 already referred to. The hollow spindle member 21 is thereby provided with bearing supports at, or substantially at, its opposite ex- In order to rotate the hollow spindle 21 within the casing 10, a pulley 23 is mounted on the spindle 21 so as to rotate the'same` when the pulley itself is rotated. Itwill be seen that the positionof the pulley 23 is adjacent the rearmost extremity of the casing 10 and that an axially extending hollow flange member 24 projects from the forward face of the pulley 23 into guarding or protecting relation to the lock nut 18 and the finger piece 25 by which the bearing bushing 17 is adjustedin its seat. With this structural arrangement the adjusting members 18 and 25 are protected from accidental moveinentbythe hands of the operator. Y On the other hand the covering up of these normally exposed members prevents injury that might otherwise occur to the hands of the operator using the device. The hand piece is throuoh this arrangement left wholly free from o structing parts from the forward edge of the pulley flange member 24 to the extreme tip portion of the casing 10.

An important feature of the invention resides in the construction of the spindle. by which the tool shafts are held in place in the device. This construction includes a longitudinally adjustable shaft or core member 27 which has a screw-threaded relation with the. rearmost extremity of thefhollow spindle member 21 as at 28 and extends forwardly into the hollow spindle member 21 to a position within the rear portion of the journal piece 22 carried by the end of hollow spindle member 21. The forward extremity of the shaft 27 is hollowed out as at 29 to receive'the end of the shaft 30 of a drill or other tool. The extreme forward portion of' the hollow end of the shaft 27 is arranged to engage the rearmost end of a hollow chuck member 32 which is longitudinally slit inwardly from its opposite ends for a portion of its length as at The extremities of the -chuck member 32 are beveled as is shown at 34 for engaging correspondingly beveled portions formed in the journal piece 22 and on the terminal portion of the shaft 27. The beveled engagement of these parts is such that pressure exerted against the chuck meinber 32 by the longitudmal movement of the shaft 27 compresses or forces the flexible end portions of the chuck 32,inwardly against the tool shaft 3() which may be contained therein. It will be seen that the clamping action which is thus exerted by the chuck member 32 against the contained shaft part 3() will hold the tool rigidly in its operating position. Not only is theitool held firmly in its operating position by the structural arrangement referred to, but the passing of the tool shaft through the bearing member 12, the journal piece 22, the chuck 32, and tothe hollowed-out portion 29 of the shaft 27 ,provides for the positivealigning of the tool shaft 3() withthe axis of rotation of the spindle. The result is that the tool is smoothly driven without lateral vibration so that effective work can be accomplished thereby.

The spindle member 21 is driven through a pulley 23 mounted on the spindle by means of a split clamping flange 36 formed on the pulley and a nut cooperating with said flange. The chuck is operated to clamp or release the drill by rotation of knurled 'finger piece 37.

In addition to the operating of the chuck 1n the manner described, the entire inner spindle and chuck structure may be readily removed from their positions in the hollow spindle member 21. This is accomplished by the simple withdrawal of the shaft 27 from its position in the hollow spindle member 21 by turning the threaded portion `28 of the shaft from itsengagement with the inner end of the hollow spindle member 21. The shaft 27 may then be completely withdrawn `from its position as will be clear 'whereupon the chuck member 32 will drop through the hollow member 21 and out throughithe open end thereof.

The chuck member is as readily placed in position within the hollow member 21 by merely dropping it'into the open bore of the hollow shaft 21 and placing the inner no'l shaft 27 in position. The inner shaft 27 will inevitably take its proper engaging position with the rearmost end of the chuck 32 because of the angular disposition of the interengaging parts.

The supporting bracket member 15 is swiveled on the shaft 16 as has already been stated, the shaft 16 being seated in a pulley supporting member 4() on which the pulleys 41 are mounted in flanking relation thereto. The position of the pulleys 41 is so related to that of the pulley 23 that a belt 42 passing around the pulleys 41 and over the pulley 23 extend to a suitable driving pulley not shown. A universal joint connection is thus provided which insures a proper driving position of the pulley 23 in any position in which the hand piece may be held. The pulley supporting member 40 has hinged relation with a socket member 43 which receives the end of a stem not shown on a bracket arm carried by the power supplying device. The spindle member 15 is provided in the under portion thereof with anv oil receiving opening 44 which, when the parts are inverted, leads to a corresponding opening 45 passing through the sleeve 14 and the Wall of the casing 10. By rotating the casing 10 in its seat in the bracket 15 until aligned marks which may be provided are brought into proper position, oil dropped into the opening 44 will pass through the openings 45 into the annular channel 46 between the casing 10 and the rotatable hollow spindle member 2l. The oil having reached this chamber Will find its way to all parts of the relatively moving portions of the spindle and casing structure.

It will be seen that the structure thus pro` vided is relatively light in weight since all but the bearing or journal parts are formed of light-weight metal. The all metal construction provides for the complete sterilization of the device. The unitary structure of the entire length of the hand piece provides a simplified and improved construction. The simplified means for taking apart the construction Without the use or tools is a valuable feature of the invention.

The device as a whole characterized by its simplicity of construction and the facility which is provided for adjusting or assembling the parts.

What is claimed is 1. In a dental drill head, a cylindrical casing having a spindle mounted therein, a bearing sleeve secured about said casing, a bracket rotatably supporting said bearing sleeve, an adjustable bearing mounted in one end of the casing, and a single means for holding said bearing in adjusted position and for holding said casing in position in said bracket.

2. In a dental drill head, an all-metal cylindrical casing having a converging nose piece at one end forming a bearing for a spindle, a bracket member in which the casing is swiveled adjacent the other end, a bearing bushing having a screw-threaded relation with the inner wall of the swiveled end of the casing for longitudinal adjustment therein, said bushing projecting through the open end of the casing, a lock nut operating on the projecting end of the bushing and adapted to engage the end of the casing and the bracket to lock the bushing in adjusted position and hold the casing in swiveled position in the bracket.

3. In a dental drill head, a cylindrical casing formed of light-Weight metal and hav` ing an extension ti member forming a bearing for a spind e, a bearing member mounted in longitudinally adjustable relation in the other end of the casing, a lock nut adapted to be received on the bearing member and to be brought into locking engagement with the end of the casing, a spindle housed in said casing and journaled in said bearings, a pulley mounted on the spindle in driving relation thereto, and an axially extending circular ange on the pulley arranged to serve as a guard for the lock nut and exposedend of the bearing.

In testimony whereof we affix our signatures.

HERMAN n. s. oHAYEs. AUGUST P. JUReENsEN. 

